Anechoic chamber

While a darkroom is a space that blocks light from the outside, an anechoic chamber is a space that blocks electromagnetic waves from the outside. An anechoic chamber not only shields electromagnetic waves from outside, but also prevents electromagnetic waves generated inside from leaking out, and its interior walls are made of materials that absorb electromagnetic waves without reflecting them. Anechoic chambers are used for electromagnetic compatibility (EMC) testing of electrical and electronic equipment, as well as for testing wireless devices.